[PATCH 6/9] virtio_balloon: remove the balloon-kvm file system

From: Christoph Hellwig
Date: Tue Mar 09 2021 - 10:57:03 EST


Just use the generic anon_inode file system.

Signed-off-by: Christoph Hellwig <hch@xxxxxx>
---
drivers/virtio/virtio_balloon.c | 30 +++---------------------------
1 file changed, 3 insertions(+), 27 deletions(-)

diff --git a/drivers/virtio/virtio_balloon.c b/drivers/virtio/virtio_balloon.c
index cae76ee5bdd688..1efb890cd3ff09 100644
--- a/drivers/virtio/virtio_balloon.c
+++ b/drivers/virtio/virtio_balloon.c
@@ -6,6 +6,7 @@
* Copyright 2008 Rusty Russell IBM Corporation
*/

+#include <linux/anon_inodes.h>
#include <linux/virtio.h>
#include <linux/virtio_balloon.h>
#include <linux/swap.h>
@@ -42,10 +43,6 @@
(1 << (VIRTIO_BALLOON_HINT_BLOCK_ORDER + PAGE_SHIFT))
#define VIRTIO_BALLOON_HINT_BLOCK_PAGES (1 << VIRTIO_BALLOON_HINT_BLOCK_ORDER)

-#ifdef CONFIG_BALLOON_COMPACTION
-static struct vfsmount *balloon_mnt;
-#endif
-
enum virtio_balloon_vq {
VIRTIO_BALLOON_VQ_INFLATE,
VIRTIO_BALLOON_VQ_DEFLATE,
@@ -805,18 +802,6 @@ static int virtballoon_migratepage(struct balloon_dev_info *vb_dev_info,

return MIGRATEPAGE_SUCCESS;
}
-
-static int balloon_init_fs_context(struct fs_context *fc)
-{
- return init_pseudo(fc, BALLOON_KVM_MAGIC) ? 0 : -ENOMEM;
-}
-
-static struct file_system_type balloon_fs = {
- .name = "balloon-kvm",
- .init_fs_context = balloon_init_fs_context,
- .kill_sb = kill_anon_super,
-};
-
#endif /* CONFIG_BALLOON_COMPACTION */

static unsigned long shrink_free_pages(struct virtio_balloon *vb,
@@ -909,17 +894,11 @@ static int virtballoon_probe(struct virtio_device *vdev)
goto out_free_vb;

#ifdef CONFIG_BALLOON_COMPACTION
- balloon_mnt = kern_mount(&balloon_fs);
- if (IS_ERR(balloon_mnt)) {
- err = PTR_ERR(balloon_mnt);
- goto out_del_vqs;
- }
-
vb->vb_dev_info.migratepage = virtballoon_migratepage;
- vb->vb_dev_info.inode = alloc_anon_inode_sb(balloon_mnt->mnt_sb);
+ vb->vb_dev_info.inode = alloc_anon_inode();
if (IS_ERR(vb->vb_dev_info.inode)) {
err = PTR_ERR(vb->vb_dev_info.inode);
- goto out_kern_unmount;
+ goto out_del_vqs;
}
vb->vb_dev_info.inode->i_mapping->a_ops = &balloon_aops;
#endif
@@ -1016,8 +995,6 @@ static int virtballoon_probe(struct virtio_device *vdev)
out_iput:
#ifdef CONFIG_BALLOON_COMPACTION
iput(vb->vb_dev_info.inode);
-out_kern_unmount:
- kern_unmount(balloon_mnt);
out_del_vqs:
#endif
vdev->config->del_vqs(vdev);
@@ -1070,7 +1047,6 @@ static void virtballoon_remove(struct virtio_device *vdev)
if (vb->vb_dev_info.inode)
iput(vb->vb_dev_info.inode);

- kern_unmount(balloon_mnt);
#endif
kfree(vb);
}
--
2.30.1